Semiconductor device including contact structure, method of fabricating the same, and electronic system including the same

1. A semiconductor device, comprising:

a gate structure on a semiconductor substrate;

an impurity region at a side of the gate structure, the impurity region being within the semiconductor substrate;

an interlayer insulating layer covering the gate structure and the impurity region;

a contact structure extending through the interlayer insulating layer and connected to the impurity region, the contact structure including a first contact structure having a side surface surrounded by the interlayer insulating layer, and a second contact structure penetrating into the impurity region and having a side surface surrounded by the impurity region; and

an insulating region in the impurity region under the second contact structure, wherein the impurity region is a source or drain region that surrounds side surfaces and a bottom surface of the insulating region.

2. The semiconductor device as claimed in claim 1 , wherein a width of the insulating region is greater than a width of the contact structure.

3. The semiconductor device as claimed in claim 1 , wherein the insulating region extends through the impurity region.

4. The semiconductor device as claimed in claim 1 , wherein the insulating region includes a silicon oxide.

5. The semiconductor device as claimed in claim 1 , wherein the insulating region includes a silicon germanium oxide.

6. The semiconductor device as claimed in claim 1 , wherein a height of the second contact structure is greater than a quarter of a width of the second contact structure.

7. The semiconductor device as claimed in claim 1 , further comprising a silicon germanium region under the insulating region.

8. The semiconductor device as claimed in claim 7 , wherein the silicon germanium region surrounds a bottom and a side surface of the insulating region.

9. The semiconductor device as claimed in claim 1 , wherein the second contact structure includes a barrier layer on a sidewall thereof and includes a contact plug on the barrier layer.

10. The semiconductor device as claimed in claim 1 , further comprising

a metal silicide layer surrounding a sidewall of the second contact structure.

11. A semiconductor device, comprising:

an impurity region;

an insulating layer on the impurity region;

a conductor extending into the impurity region through the insulating layer; and

an insulating region arranged within the impurity region, the insulating region on a lower end portion of the conductor that extends into the impurity region, wherein the impurity region is a source or drain region that surrounds side surfaces and a bottom surface of the insulating region.

12. The semiconductor device as claimed in claim 11 , wherein the impurity region includes a doped silicon and the insulating region includes a silicon oxide.

13. The semiconductor device as claimed in claim 11 , wherein the conductor includes:

a first conductor penetrating the insulating layer, and

a second conductor extending into the impurity region, a length of the second conductor extending into the impurity region is larger than a quarter of a width of the second conductor.

14. The semiconductor device as claimed in claim 13 , further comprising

a barrier layer on a sidewall and a bottom surface of the second conductor.

15. The semiconductor device as claimed in claim 13 , further comprising

a metal silicide layer surrounding a sidewall of the second conductor.

16. A semiconductor device, comprising:

a gate structure on an upper surface of a semiconductor substrate;

an impurity region adjacent to the gate structure, the impurity region being within the semiconductor substrate;

an interlayer layer covering the gate structure and the impurity region;

a contact structure including a first portion extending through the interlayer layer and a second portion extending within the impurity region; and

an insulating region within the impurity region, the insulating region being between a lower surface of the semiconductor substrate and a lower surface of the second portion of the contact structure, wherein the impurity region is a source or drain region that surrounds side surfaces and a bottom surface of the insulating region.

17. The semiconductor device as claimed in claim 16 , wherein the insulating region is in direct contact with the lower surface of the second portion of the contact structure.

18. The semiconductor device as claimed in claim 17 , wherein:

a height of the second portion of the contact structure is greater than a quarter of a width of the contact structure,

the second portion of the contact structure is entirely within the impurity region, and

the first portion of the contact structure is above the impurity region.

19. The semiconductor device as claimed in claim 18 , wherein:

a width of the insulating region is greater than the width of the contact structure, and

the insulating region is entirely within the impurity region.

20. The semiconductor device as claimed in claim 16 , wherein:

the interlayer layer is directly on the impurity region,

a height of the contact structure is greater than a height of the interlayer layer, and

along a width of the contact structure, the insulating region separates at least a portion of the lower surface of the second portion of the contact structure from the impurity region.

21. The semiconductor device as claimed in claim 1 , wherein the impurity region surrounds all side surfaces and the bottom surface of the insulating region.